Pilot hydraulic control device and working machine

Abstract

The utility model relates to the technical field of hydraulic control, discloses a pilot hydraulic control device and an operating machine, and aims to realize automatic establishment of pilot pressure by using a single pump and simplify the pilot hydraulic control device. The pilot hydraulic control device comprises a hydraulic oil tank; a working pump; the first oil way and the second oil way are communicated with each other and are both communicated with an oil outlet of the working pump; the multi-way valve is communicated with an oil outlet of the working pump through a first oil way; the pilot valve is communicated with an oil outlet of the working pump through a second oil way, and the pilot valve is communicated with the pilot end of the multi-way valve; the throttling element is communicated with the first oil way through the multi-way valve; the throttling element is provided with a throttling hole, and the first oil way is selectively communicated with or disconnected from the throttling hole; when the first oil way communicates with the throttling hole, first pressure is generated on the second oil way, so that the pilot valve is opened through the first pressure; and an oil inlet of the working pump and oil return ports of the multi-way valve, the pilot valve and the throttling element are all communicated with the hydraulic oil tank.

Description

Technical Field

[0001] This utility model relates to the field of hydraulic control technology, specifically to a pilot hydraulic control device and a working machine. Background Technology

[0002] Traditional pilot hydraulic control devices require a dual-pump structure (main pump + pilot pump). The pilot pump independently provides pilot pressure and needs to be equipped with relief valves, pressure selection valves, etc. This solution has the problems of a large number of components, high cost, and system complexity. Utility Model Content

[0003] In view of this, the present invention provides a pilot hydraulic control device and working machine with a simple structure that can use a single pump to generate pilot pressure.

[0004] In a first aspect, this utility model provides a pilot hydraulic control device, comprising: a hydraulic oil tank; a working pump; a first oil circuit and a second oil circuit, the first oil circuit and the second oil circuit being connected and both connected to the oil outlet of the working pump; a multi-way valve, connected to the oil outlet of the working pump through the first oil circuit; a pilot valve, connected to the oil outlet of the working pump through the second oil circuit, and the pilot valve being connected to the pilot end of the multi-way valve; a throttling element, connected to the first oil circuit through the multi-way valve; the throttling element is provided with a throttling orifice, and the first oil circuit can selectively connect to or disconnect from the throttling orifice; when the first oil circuit is connected to the throttling orifice, it is suitable for generating a first pressure in the second oil circuit to open the pilot valve through the first pressure; wherein, the oil inlet of the working pump and the oil return ports of the multi-way valve, the pilot valve, and the throttling element are all connected to the hydraulic oil tank.

[0005] In one optional embodiment, the throttling element has a throttling element inlet, a throttling element return port, and a throttling element control port. The throttling element inlet is connected to a first oil circuit via a multi-way valve, the throttling element return port is connected to a hydraulic oil tank, and the throttling element control port is connected to a second oil circuit. The throttling element control port is adapted to control the connection or disconnection of the throttling element inlet and return port with the throttling orifice according to the pressure of the second oil circuit.

[0006] In one alternative implementation, the throttling element is disposed within the pilot valve.

[0007] In one alternative implementation, the first pressure is 5 bar to 60 bar.

[0008] In one optional embodiment, the system further includes a steering system disposed on a first oil circuit; the steering system has a steering system inlet and a steering system overflow outlet, the steering system inlet being connected to the outlet of the working pump, and the steering system overflow outlet being connected to the inlet of the multi-way valve; wherein, a second oil circuit is connected between the outlet of the working pump and the steering system inlet; or, the second oil circuit is connected to the steering system overflow outlet.

[0009] In one optional embodiment, a pressure reducing valve is also included, which is disposed on the second oil line; the working port of the pressure reducing valve is connected to the oil inlet of the pilot valve.

[0010] In one optional embodiment, a one-way valve is also included, which is disposed in the second oil circuit; the oil inlet of the one-way valve is connected to the working oil port of the pressure reducing valve, and the oil outlet of the one-way valve is connected to the oil inlet of the pilot valve.

[0011] In one alternative embodiment, an accumulator is also included, which is disposed in the second oil circuit; the accumulator is connected to the oil outlet of the check valve.

[0012] In one alternative embodiment, a pressure reducing valve is disposed within a pilot valve; and / or, a check valve is disposed within a pilot valve.

[0013] Secondly, this utility model also provides a working machine, including: the pilot hydraulic control device as described above.

[0014] Using the technical solution of this utility model, a multi-way valve and a pilot valve are respectively connected to the outlet of the working pump through a first oil circuit and a second oil circuit. By setting a throttling device downstream or at the end of the multi-way valve, the throttling device is connected to the first oil circuit through the multi-way valve. When the hydraulic oil output from the outlet of the working pump enters the throttling orifice through the multi-way valve, the throttling orifice causes back pressure, i.e., a first pressure, to be generated in the first oil circuit. This, in turn, causes a first pressure to be generated in the second oil circuit connected to the first oil circuit. The second oil circuit transmits this first pressure to the pilot valve, forming the pilot pressure for the pilot valve to start. In the technical solution of this utility model, by setting a first oil circuit and a second oil circuit, and setting a throttling device in the first oil circuit, the pilot hydraulic control device can automatically establish pilot pressure using a single pump, without the need for additional pilot pumps or other components, thus simplifying the structure of the pilot hydraulic control device. Attached Figure Description

[0015] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the pilot hydraulic control device according to Embodiment 1 of this utility model;

[0017] Figure 2 for Figure 1 A magnified view of a portion of the radius R;

[0018] Figure 3 This is a schematic diagram of the pilot hydraulic control device according to Embodiment 2 of this utility model;

[0019] Figure 4 This is a schematic diagram of the pilot hydraulic control device according to Embodiment 3 of this utility model;

[0020] Figure 5 This is a schematic diagram of the pilot hydraulic control device according to Embodiment 4 of this utility model;

[0021] Figure 6 This is a schematic diagram of the pilot hydraulic control device according to Embodiment 5 of this utility model;

[0022] Figure 7 This is a schematic diagram of the pilot hydraulic control device according to Embodiment Six of this utility model.

[0023] Explanation of reference numerals in the attached figures:

[0024] 1. Hydraulic oil tank; 2. Working pump; 3. Multi-way valve; 4. Pilot valve; 5. Steering system; 51. Steering system inlet; 52. Steering system overflow port; 6. Throttling element; 61. Throttling orifice; 62. Connecting channel; 63. Throttling element inlet; 64. Throttling element return port; 65. Throttling element control port; 7. Pressure reducing valve; 8. Check valve; 9. Accumulator; 10. First oil circuit; 11. Second oil circuit. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0026] According to an embodiment of the present invention, a pilot hydraulic control device is provided, which includes a hydraulic oil tank, a working pump, a multi-way valve, a pilot valve, and a throttling element.

[0027] Specifically, the pilot hydraulic control device further includes a first oil circuit and a second oil circuit connected to each other. Both the first and second oil circuits are connected to the outlet of the working pump, and the inlet of the working pump is connected to the hydraulic oil tank. A multi-way valve is connected to the outlet of the working pump through the first oil circuit, and a pilot valve is connected to the outlet of the working pump through the second oil circuit, with the pilot end of the pilot valve also connected to the multi-way valve. A throttling element is connected to the first oil circuit through the multi-way valve, and the throttling element has a throttling orifice. The first oil circuit can selectively connect to or disconnect from the throttling orifice. When the first oil circuit is connected to the throttling orifice, it is suitable for generating a first pressure in the second oil circuit to open the pilot valve. The inlet of the working pump, as well as the return ports of the multi-way valve, pilot valve, and throttling element, are all connected to the hydraulic oil tank.

[0028] Using the technical solution of this utility model, the multi-way valve and the pilot valve are respectively connected to the oil outlet of the working pump through the first oil circuit and the second oil circuit. By setting a throttling element downstream or at the end of the multi-way valve, the throttling element is connected to the first oil circuit through the multi-way valve. When the hydraulic oil output from the oil outlet of the working pump enters the throttling orifice through the multi-way valve, the throttling orifice causes back pressure, i.e., the first pressure, to be generated in the first oil circuit. This, in turn, causes the second oil circuit connected to the first oil circuit to also generate the first pressure. The second oil circuit transmits this first pressure to the pilot valve, forming the pilot pressure for starting the pilot valve.

[0029] In the technical solution of this utility model, by setting up a first oil circuit and a second oil circuit, and setting a throttling device on the first oil circuit, the pilot hydraulic control device can automatically establish pilot pressure using a single pump, without the need to set up an additional pilot pump or other related components, thus simplifying the pilot hydraulic control device.

[0030] The following is combined Figures 1 to 7 The following describes specific embodiments of this utility model.

[0031] Example 1

[0032] In this embodiment, as Figure 1 and Figure 2 As shown, the pilot hydraulic control device includes a hydraulic oil tank 1, a working pump 2, a multi-way valve 3, a pilot valve 4, a throttling device 6, and a first oil circuit 10 and a second oil circuit 11 that are connected to each other.

[0033] Specifically, the inlet of the working pump 2 is connected to the hydraulic oil tank 1, and the outlet of the working pump 2 is connected to the first oil passage 10 and the second oil passage 11. The multi-way valve 3 is connected to the outlet of the working pump 2 through the first oil passage 10, and the pilot valve 4 is connected to the outlet of the working pump 2 through the second oil passage 11. Understandably, in this embodiment, the hydraulic oil output from the outlet of the working pump 2 is divided into two paths: one path flows to the multi-way valve 3 through the first oil passage 10, and the other path flows to the pilot valve 4 through the second oil passage 11. Furthermore, the pilot valve 4 is connected to the pilot end of the multi-way valve 3, so that after the pilot valve 4 is opened, it can push the valve core of the multi-way valve 3 through the pilot end of the multi-way valve 3 to complete the corresponding action of the working device.

[0034] Furthermore, the throttling element 6 is connected to the first oil passage 10 via the multi-way valve 3. The throttling element 6 is provided with a throttling orifice 61, and the first oil passage 10 can be selectively connected to or disconnected from the throttling orifice 61. When the first oil passage 10 is connected to the throttling orifice 61, it is suitable for generating a first pressure on the second oil passage 11, so as to open the pilot valve 4 through the first pressure. The return ports of the multi-way valve 3, the pilot valve 4, and the throttling element 6 are all connected to the hydraulic oil tank 1.

[0035] The pilot hydraulic control device in this embodiment is implemented as follows: When the machine is initially started from a stopped state, the hydraulic oil pressure output from the outlet of the working pump 2 is relatively low. At this time, the first oil circuit 10 is connected to the throttle orifice 61. Through the action of the throttle orifice 61, a first pressure is established on the second oil circuit 11 to provide the initial starting pressure, i.e., pilot pressure, for the pilot valve 4. After the machine starts to operate, the pressure of the hydraulic oil output from the outlet of the working pump 2 increases. At this time, the first oil circuit 10 is disconnected from the throttle orifice 61, and the first oil circuit 10 switches back to the normal connected oil circuit, and the machine begins to work normally.

[0036] More specifically, the multi-way valve 3 has a multi-way valve inlet, a multi-way valve return port, a multi-way valve pilot end, a multi-way valve working end, and an internal oil passage connecting the multi-way valve inlet, multi-way valve return port, multi-way valve pilot end, and multi-way valve working end. The multi-way valve inlet is also... Figure 1 The P port on the multi-way valve 3 is the return port of the multi-way valve. Figure 1 The T port on the multi-way valve 3 is the pilot end of the multi-way valve. Figure 1 The ports a1, b1, a2, b2, etc. on the multi-way valve 3 are the working ends of the multi-way valve. Figure 1 The multi-way valve 3 has ports A1, B1, A2, and B2. The inlet of the multi-way valve is connected to the first oil circuit 10, the return port of the multi-way valve is connected to the hydraulic oil tank 1, and the working end of the multi-way valve is connected to the working device. The working end of the multi-way valve is used to drive the working device.

[0037] One end of the throttling orifice 61 of the throttling element 6 is connected to the oil inlet of the multi-way valve through the internal oil passage of the multi-way valve, and the other end of the throttling orifice 61 is connected to the oil return port of the multi-way valve, so as to generate back pressure, i.e. the first pressure mentioned above, through the multi-way valve 3 in the first oil passage 10.

[0038] Pilot valve 4 has a pilot valve inlet, a pilot valve return port, and a pilot valve working end. The pilot valve inlet is also... Figure 1 The P port on pilot valve 4 is the pilot valve return port, which is... Figure 1 The T port on pilot valve 4 is the working end of the pilot valve. Figure 1 The pilot valve 4 has ports A1, B1, A2, and B2. The pilot valve inlet is connected to the second oil circuit 11, so that the first pressure is transmitted to the pilot valve inlet through the second oil circuit 11 to open the pilot valve 4. The pilot valve return port is connected to the hydraulic oil tank 1. The pilot valve working end is connected to the pilot end of the multi-way valve. The pilot valve working end is used to push the corresponding valve core of the multi-way valve 3 through the pilot end of the multi-way valve to realize the action of the corresponding working device.

[0039] Understandably, the pilot hydraulic control device also includes a pilot handle, which is connected to the pilot valve 4. By pushing the pilot handle, in conjunction with the pilot pressure (i.e., the first pressure) at the oil inlet of the pilot valve, a secondary pressure is generated at the working end of the pilot valve, which in turn pushes the corresponding valve core of the multi-way valve 3.

[0040] This invention does not limit the specific structure of the multi-way valve 3 and the pilot valve 4; their specific structures can be adapted to the type of machinery used in the pilot hydraulic control device. Correspondingly, the working device connected to the working end of the multi-way valve 3 also depends on the type of machinery used in the pilot hydraulic control device. For example, the machinery used in the pilot hydraulic control device can be a loader, and the working device can include a boom cylinder and a bucket cylinder, etc.

[0041] Furthermore, such as Figure 2 As shown, the throttling element 6 has a throttling element inlet 63, a throttling element return port 64, and a throttling element control port 65. The throttling element inlet 63 is connected to the inlet of the multi-way valve through the internal oil passage of the multi-way valve, so as to realize the connection with the first oil passage 10 through the multi-way valve 3. The throttling element return port 64 is connected to the hydraulic oil tank 1 and to the return port of the multi-way valve. The throttling element control port 65 is connected to the second oil passage 11. The throttling element control port 65 is adapted to control the connection or disconnection of the throttling element inlet 63 and the throttling element return port 64 with the throttling orifice 61 according to the pressure of the second oil passage 11, so as to realize the selective connection or disconnection of the first oil passage 10 with the throttling orifice 61.

[0042] For example, the throttling device 6 is further provided with a connecting channel 62. When the pressure of the throttling device control port 65 is less than the second pressure, the throttling device inlet port 63 is connected to the throttling device return port 64 through the throttling orifice 61. When the pressure of the throttling device control port 65 is greater than or equal to the second pressure, both the throttling device inlet port 63 and the throttling device return port 64 are disconnected from the throttling orifice 61, and the throttling device inlet port 63 is connected to the throttling device return port 64 through the connecting channel 62.

[0043] In practical applications, when the machine is initially started from a stopped state, no pressure is generated in the second oil circuit 11. Therefore, the pressure at the throttle control port 65 is less than the second pressure. At this time, the throttle inlet port 63 is connected to the throttle return port 64 through the throttle orifice 61, thereby generating the aforementioned first pressure in the second oil circuit 11 to activate the pilot valve. After the machine starts operating, the pressure of the hydraulic oil output from the outlet of the working pump 2 gradually increases. When the pressure delivered from the second oil circuit 11 to the throttle control port 65 is greater than or equal to the second pressure, the throttle inlet port 63 is connected to the throttle return port 64 through the connecting channel 62, so that the first oil circuit 10 switches to the normal circuit, avoiding energy waste and ensuring the energy efficiency of the pilot hydraulic control device.

[0044] For example, the throttling element 6 can be a throttling slide valve, a hydraulic valve, a speed control valve, etc., as long as it can generate back pressure on the first oil circuit 10, so that pilot pressure is generated on the second oil circuit 11.

[0045] Understandably, the second pressure is the critical pressure required to move the valve core of the throttling element 6, and the magnitude of this second pressure can be adjusted adaptively according to actual conditions. Specifically, this second pressure can be between 5 bar and 50 bar.

[0046] For example, the second pressure can be 25 bar. In this case, when the pressure of the hydraulic oil output from the outlet of the working pump 2 is greater than or equal to 25 bar, it can push the valve core of the throttling element 6 to move, so that the oil inlet 63 and the oil return 64 of the throttling element are disconnected from the throttling orifice 61 and connected through the connecting channel 62. Of course, the second pressure can also be 5 bar, 10 bar, 15 bar, 20 bar, 30 bar, 35 bar, 40 bar, 45 bar, 50 bar, or any other value from 5 bar to 50 bar.

[0047] Furthermore, in this embodiment, the throttling element 6 can be disposed within the pilot valve 4, that is, the throttling element 6 and the pilot valve 4 are integrated into a single structure, in order to further simplify the number of components in the pilot hydraulic control device and reduce the overall layout difficulty. Of course, in other embodiments, the throttling element 6 can also be disposed outside the pilot valve 4 and connected downstream or at the end of the pilot valve 4.

[0048] Furthermore, depending on the type of operating machinery, the pilot pressure required to open the pilot valve 4 is usually 5 bar to 60 bar. The aforementioned first pressure can be 5 bar to 60 bar to ensure the opening of the pilot valve 4.

[0049] Understandably, the hydraulic oil pressure decreases after flowing through the throttle orifice 61, thereby creating a pressure difference before and after the throttle orifice 61. Specifically, a pressure difference is generated between the oil inlet 63 and the oil outlet of the throttle element 6. This pressure difference causes the first pressure to be generated in the first oil circuit 10. The pressure difference before and after the throttle orifice 61 can be set according to actual conditions to control the magnitude of the first pressure, so that the first pressure reaches the pilot pressure required by the pilot valve 4.

[0050] In this embodiment, the pilot hydraulic control device further includes a steering system 5, which is disposed on the first oil circuit 10. The steering system 5 has a steering system inlet 51 and a steering system overflow port 52. The steering system inlet 51 is connected to the outlet of the working pump 2, and the steering system overflow port 52 is connected to the inlet of the multi-way valve 3. A second oil circuit 11 connects the outlet of the working pump 2 and the steering system inlet 51. That is, the hydraulic oil output from the outlet of the working pump 2 enters the first oil circuit 10, then enters the steering system 5 through the steering system inlet 51, flows into the multi-way valve 3 through the steering system overflow port 52, and then flows into the throttle orifice 61. There is often a certain pressure loss between the steering system inlet 51 and the steering system overflow port 52, which can also generate a certain back pressure upstream of the steering system 5.

[0051] In this embodiment, the first pressure is equal to the pressure loss between the steering system inlet 51 and the steering system overflow port 52 plus the pressure difference generated before and after the throttle orifice 61.

[0052] Furthermore, the pressure loss between the steering system inlet 51 and the steering system overflow port 52 is typically 5 bar to 15 bar, and the pressure difference generated before and after the throttle orifice 61 can be set to 5 to 60 bar to ensure that the first pressure can reach the pilot pressure value required by the pilot valve 4.

[0053] For example, the pilot pressure required for pilot valve 4 is 26.9 bar, and the pressure loss between the steering system inlet 51 and the steering system overflow port 52 is 6.9 bar. In this case, the pressure value generated before and after the throttle orifice 61 can be set to 20 bar. Thus, in the pilot hydraulic control device of this embodiment, the first pressure generated on the second oil circuit 11 can reach 26.9 bar, thereby enabling the opening of pilot valve 4.

[0054] Furthermore, the pilot hydraulic control device also includes a pressure reducing valve 7, which is located on the second oil circuit 11. The inlet of the pressure reducing valve 7 is directly connected to the outlet of the working pump 2 through the first oil circuit 10, and the working port of the pressure reducing valve 7 is connected to the inlet of the pilot valve 4. Figure 1 As shown, the oil inlet of the pressure reducing valve 7 is also the P port on the pressure reducing valve 7, and the working oil port of the pressure reducing valve 7 is also the A port on the pressure reducing valve 7. By setting the pressure reducing valve 7, the second oil circuit 11 can provide a stable pilot pressure to the pilot valve 4.

[0055] Furthermore, the pilot hydraulic control device also includes a one-way valve 8, which is disposed on the second oil circuit 11. The inlet of the one-way valve 8 is connected to the working port of the pressure reducing valve 7, and the outlet of the one-way valve 8 is connected to the inlet of the pilot valve 4. That is, the one-way valve 8 allows the hydraulic oil in the second oil circuit 11 to flow unidirectionally from the working port of the pressure reducing valve 7 to the inlet of the pilot valve 4. By setting the one-way valve 8, backflow of hydraulic oil at the inlet of the pilot valve can be prevented, maintaining the stability of the pilot pressure and ensuring the reliability of the pilot control signal.

[0056] Furthermore, the pilot hydraulic control device also includes an accumulator 9, which is installed on the second oil circuit 11. The accumulator 9 is connected to the outlet of the check valve 8. When the machine starts operating, the pressure of the hydraulic oil output from the outlet of the working pump 2 increases. At this time, the hydraulic oil after passing through the pressure reducing valve 7 and the check valve 8 can fill the accumulator 9 as a backup pressure source. When the working pump 2 stops working, the hydraulic oil stored in the accumulator 9 can provide pressure to the pilot valve 4, enabling the boom to complete the final descent under gravity.

[0057] The aforementioned throttling device control port 65 is connected to the second oil circuit 11, specifically between the oil outlet of the check valve 8 and the oil inlet of the pilot valve 4.

[0058] Example 2

[0059] like Figure 3 As shown, the difference between the pilot hydraulic control device in this embodiment and that in Embodiment 1 is that the throttle element 6 is disposed outside the multi-way valve 3, that is, the throttle element 6 and the multi-way valve 3 are disposed independently. Specifically, the throttle element inlet 63 is connected to the multi-way valve inlet through the internal oil passage of the multi-way valve, and the throttle element return port 64 is connected to the multi-way valve return port.

[0060] Example 3

[0061] like Figure 4 As shown, the difference between the pilot hydraulic control device in this embodiment and the first embodiment is that the second oil circuit 11 is connected to the overflow port 52 of the steering system. That is, the second oil circuit 11 is located downstream of the steering system 5. The second oil circuit 11 is connected to the oil outlet of the working pump 2 through the first oil circuit 10 and the steering system 5.

[0062] Understandably, in this embodiment, the hydraulic oil output from the outlet of the working pump 2 enters the steering system inlet 51 through the first oil passage 10. After being distributed by the internal oil passage of the steering system 5, the hydraulic oil output from the steering system overflow port 52 is divided into two paths. One path flows to the multi-way valve 3 and then into the throttle element 6. The other path flows to the pilot valve 4 through the second oil passage 11, specifically passing through the pressure reducing valve 7 and the check valve 8 in sequence before entering the pilot valve inlet.

[0063] In this embodiment, the second oil passage 11 is located downstream of the steering system 5. The first pressure on the second oil passage 11 is generated by the throttle orifice 61, that is, the first pressure is equal to the pressure difference value generated before and after the throttle orifice 61. Further, in this embodiment, the pressure difference value at the throttle orifice 61 can be set to 10 to 60 bar, so that the first pressure can meet the pilot pressure required by the pilot valve 4.

[0064] Furthermore, in this embodiment, the pressure reducing valve 7, the one-way valve 8, and the accumulator 9 are all installed on the second oil circuit 11, wherein the oil inlet of the pressure reducing valve 7 is directly connected to the steering system overflow port 52.

[0065] Example 4

[0066] like Figure 5 As shown, the pilot hydraulic control device in this embodiment and the pilot hydraulic control device in embodiment three both use the second oil circuit 11 to connect with the steering system overflow port 52. The difference between the pilot hydraulic control device in this embodiment and embodiment three is that in this embodiment, the pressure reducing valve 7 and the one-way valve 8 are both set inside the pilot valve 4, that is, integrated with the pilot valve 4 into a single structure, so as to simplify the number of components of the pilot hydraulic control device and reduce the difficulty of the overall layout.

[0067] Understandably, in other embodiments, one of the pressure reducing valve 7 and the check valve 8 may also be disposed within the pilot valve 4.

[0068] Example 5

[0069] like Figure 6 As shown, the pilot hydraulic control device in this embodiment and the pilot hydraulic control device in embodiment three both use the second oil circuit 11 to connect with the steering system overflow port 52. The difference between the pilot hydraulic control device in this embodiment and embodiment three is that in this embodiment, the pressure reducing valve 7 and the one-way valve 8 are both set inside the pilot valve 4, that is, integrated with the pilot valve 4 into a single structure, while the throttling element 6 is set outside the multi-way valve 3, that is, the throttling element 6 and the multi-way valve 3 are set independently.

[0070] Example 6

[0071] like Figure 7As shown, the pilot hydraulic control device in this embodiment and the pilot hydraulic control device in embodiment three both use the second oil circuit 11 to connect with the steering system overflow port 52. The difference between the pilot hydraulic control device in this embodiment and embodiment three is that in this embodiment, the throttle element 6 is set outside the multi-way valve 3, that is, the throttle element 6 and the multi-way valve 3 are set independently.

[0072] According to an embodiment of the present invention, another aspect provides a working machine that includes the aforementioned pilot hydraulic control device. Since the working machine of the present invention includes the pilot hydraulic control device of the present invention, it has the same technical effects as the pilot hydraulic control device of the present invention, and will not be described again here.

[0073] It should be noted that the operating machinery of this utility model includes, but is not limited to, excavators, loaders, cranes, scrapers, presses, aerial work platforms, drilling equipment, etc.

[0074] This utility model discloses a pilot hydraulic control device and operating machinery. By setting up a first oil circuit 10 and a second oil circuit 11, and installing a throttling device 6 on the first oil circuit 10, the back pressure generated in the pilot hydraulic control device is used as the pilot pressure for the cold start of the entire machine. This eliminates the need for a separate pilot pump, making the hydraulic system more integrated. Furthermore, the position of the throttling device 6 and the connection position of the oil inlet of the pressure reducing valve 7 can be flexibly selected, making it more adaptable.

[0075] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A pilot hydraulic control device characterized by comprising: The hydraulic system comprises: a hydraulic oil tank (1); a working pump (2); a first oil path (10) and a second oil path (11), which are communicated and both communicated with an oil outlet of the working pump (2); a multi-way valve (3) communicated with the oil outlet of the working pump (2) through the first oil path (10); a pilot valve (4) communicated with the oil outlet of the working pump (2) through the second oil path (11), and communicated with a pilot end of the multi-way valve (3); a throttling member (6) communicated with the first oil path (10) through the multi-way valve (3), and provided with a throttling hole (61), the first oil path (10) is selectively communicated with or disconnected from the throttling hole (61), when the first oil path (10) is communicated with the throttling hole (61), a first pressure is generated on the second oil path (11) to open the pilot valve (4) through the first pressure; wherein, an oil inlet of the working pump (2) and oil return inlets of the multi-way valve (3), the pilot valve (4) and the throttling member (6) are all communicated with the hydraulic oil tank (1).

2. The pilot hydraulic control apparatus according to claim 1, characterized by The throttling member (6) is provided with a throttling member oil inlet (63), a throttling member oil return (64) and a throttling member control oil port (65), the throttling member oil inlet (63) is communicated with the first oil path (10) through the multi-way valve (3), the throttling member oil return (64) is communicated with the hydraulic oil tank (1), and the throttling member control oil port (65) is communicated with the second oil path (11); the throttling member control oil port (65) is adapted to control the throttling member oil inlet (63) and the throttling member oil return (64) to be communicated with or disconnected from the throttling hole (61) according to the pressure of the second oil path (11).

3. The pilot hydraulic control apparatus according to claim 1, characterized by The throttling member (6) is arranged in the pilot valve (4).

4. The pilot hydraulic control apparatus according to claim 1, characterized by The first pressure is 5bar-60bar.

5. The pilot hydraulic control apparatus according to any one of claims 1-4, characterized by, The hydraulic system further comprises a steering system (5) arranged on the first oil path (10), the steering system (5) is provided with a steering system oil inlet (51) and a steering system overflow port (52), the steering system oil inlet (51) is communicated with the oil outlet of the working pump (2), and the steering system overflow port (52) is communicated with an oil inlet of the multi-way valve (3); wherein, the second oil path (11) is communicated between the oil outlet of the working pump (2) and the steering system oil inlet (51), or the second oil path (11) is communicated with the steering system overflow port (52).

6. The pilot hydraulic control apparatus according to claim 5, characterized by The hydraulic system further comprises a pressure reducing valve (7) arranged on the second oil path (11), a working oil port of the pressure reducing valve (7) is communicated with an oil inlet of the pilot valve (4).

7. The pilot hydraulic control apparatus according to claim 6, characterized by The hydraulic system further comprises a check valve (8) arranged on the second oil path (11), an oil inlet of the check valve (8) is communicated with a working oil port of the pressure reducing valve (7), and an oil outlet of the check valve (8) is communicated with the oil inlet of the pilot valve (4).

8. The pilot hydraulic control apparatus according to claim 7, characterized by Further comprising an accumulator (9) disposed on the second oil passage (11); the accumulator (9) is in communication with the oil outlet of the one-way valve (8).

9. The pilot hydraulic control apparatus according to claim 7, characterized by The pressure reducing valve (7) is disposed in the pilot valve (4); and / or, the one-way valve (8) is disposed in the pilot valve (4).

10. A work machine characterized by, Comprise: The pilot hydraulic control device according to any one of claims 1 to 9.

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